Conventional shower doors comprise a stationary frame for fixing to a wall and a movable frame that is capable of adjusting its position in relative to the stationary frame such that both frames are properly engagement with each other. In order to engage both frames, the frames have to be aligned and drilled and fasteners are used to pass through the drilled holes and fasten the frames together. The assembly method of this kind is inconvenient to operation and quite time consuming. In addition, the drilling operation can possibly make damage to the materials made of the frames, for example aluminum materials. This may affect the appearance and service life of the shower door, or even cause the shower door unusable.